<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
       *{margin: 0;padding: 0}
       ul{padding: 100px}

       /*ul li:nth-child(1){color: deeppink}*/
       /*ul li:nth-of-type(1){color: deeppink}*/

       /*
        找div底下的第一个子元素
        这个子元素必须得是span
       */
       /*div span:nth-child(1){color: deeppink}*/

       /*找div底下的第一个span子元素*/
       div span:nth-of-type(1){color: deeppink}
    </style>
</head>
<body>
    <div>
        <strong>span</strong>
        <i>i</i>
        <p>p</p>
        <em>em</em>
        <h3>h3</h3>
        <span>span</span>
    </div>


    <!--
        <ul>
          <li>1</li>
          <li>2</li>
          <li>3</li>
          <li>4</li>
          <li>5</li>
       </ul>
    -->
</body>
</html>